The invention relates to a clutch disc for a motor vehicle friction disc clutch, and particularly a clutch disc with torsional vibration dampers for both an under-load range and an idling range.
From German Utility Model No. 7,205,198 a clutch disc for a motor vehicle friction disc clutch is known in which the hub for coupling with the gear input shaft carries a toothing by means of which a radially protruding hub disc is coupled non-rotatably, except for a pre-determined rotational play, with the hub. Side discs carrying the friction linings of the clutch disc are rotatably mounted on the hub axially on both sides of the hub disc. Damper springs which can be stressed in the relative rotation of the hub disc and the two side discs are arranged in windows of these discs. The damper springs together with the hub disc and the two side discs are parts of a torsional vibration damper for the under-load range of the clutch. A vibration damper for the idling range is arranged axially laterally of this under-load vibration damper. The idling vibration damper likewise comprises a hub disc seated non-rotatably on the hub and, axially on both sides of the hub disc, two side discs connected with one another and with the side disc unit of the under-load vibration damper.
In this clutch disc the input parts of the two vibration dampers, formed by the side discs, are firmly connected with one another. The idling vibration damper is stressed with the under-load vibration damper over the whole angle of relative rotation of the latter. Since only relatively little space is available for the installation of the damping springs of the idling vibration damper, the maximum angle of rotation is limited. Furthermore, the attunement of the spring characteristics of the idling vibration damper is problematical.
From German Pat. No. 1,680,049 a clutch disc is known in which the friction linings are held on a hub disc which is rotatable in relation to the hub. The hub disc is arranged axially between two side discs which in turn are secured to a hub sleeve. The hub sleeve encloses the actual hub of the clutch disc and is coupled non-rotatably but with play in the circumferential direction with the hub. The hub disc and the two side discs together with damper springs again are parts of a torsional vibration damper for the under-load range. Axially laterally of the under-load vibration damper, there is arranged a torsional vibration damper for the idling range, which likewise comprises a hub disc coupled non-rotatably with the hub, two side discs axially on both sides of this hub disc, and damper springs. The side discs of the idling vibration damper are firmly connected with the side discs of the under-load vibration damper. In this clutch disc the input parts of the idling vibration damper are coupled with the output parts of the under-load vibration damper. Thus, in fact the attunement of the idling vibration damper is facilitated, but the axial extent of the clutch disc is relatively great.
From Federal Republic of Germany Spec. No. 2,814,240 a clutch disc is known on the hub of which a hub disc is seated. The hub disc is connected with the hub through a toothing with rotational play, but otherwise non-rotatably. Axially on both sides of the hub disc there are arranged side discs which are connected with one another to form a unit which is rotatable in relation to the hub disc and carries the friction linings of the clutch disc. The hub disc and the side discs together with damper springs are parts of a vibration damper for the under-load range. Damper springs tuned to the idling range are seated in apertures of the toothing, radially between the hub and the hub disc. This clutch disc requires little space in the axial direction. However, it cannot be used when the important point is to transmit great torques through the clutch disc. The idling damper springs fitted in the region of the toothing weaken the toothing cross-section available for torque transmission. Thus, the number and size of the idling damper springs are limited.
Accordingly, the present invention is directed toward provision of a clutch disc for a motor vehicle friction disc clutch with torsional vibration dampers both for the under-load range and for the idling range. The clutch disc should be suitable for the transmission of relatively great torques and nevertheless have an axially space-saving construction. More particularly, the idling torsional damper is to be accommodated in protected manner and bridged over in the operation of the under-load torsional damper.